1. Field of the Invention
This invention relates to gas flow heat exchangers and more particularly, to such devices utilizing heat pipes for facilitating heat exchange between separate gas passages.
2. Description of the Prior Art
In the past, it has been known to use air-to-gas heat exchangers wherein gas is conveyed adjacent air in opposite directions to transfer heat from the gas to the air. The air is heated for use at various locations, and the gas is cooled for environmentally safe exhaust into the atmosphere. A major problem with air-to-gas heat exchangers in the past has been air leakage into the gas passages. Such leakage not only reduces the effective thermal efficiency, but also may require the installation of larger fans or blowers and with attendant additional electrical energy required to drive such gas or air moving devices. Regenerative type heat exchangers further suffer from the disadvantage that alternate heating and cooling of the thermal storage and movement structure causes scaling, cracking and accelerated corrosion and erosion of the assembly. Heat pipe type heat exchangers overcome most of these problems, but usually require a complex assembly technique and a rigid installation which frequently is costly and difficult to fabricate.
So-called "heat pipes" are effective heat transfer elements by virtue of their containment of volatile liquid which cycles between liquid and vapor phases and circulates between hot and cold regions, transferring the heat of vaporization from the warmer to the cooler region. It is desired to provide a heat pipe type heat exchanger which uses heat pipes of a design easily mass produced. Moreover, it is desired to simultaneously obtain a heat pipe type heat exchanger which is easily assembled in the field at the point of use, but which can be quickly broken down for shipping and repair. However, a particular problem with such heat exchangers in the past has been the development of satisfactory arrangements for sealing the separators between the gas and the air passages in order to prevent leaking and reduce thermal and energy losses.